TY  - GEN
A1  - Heuer, Leonie
A1  - Orland, Andreas
T1  - Cooperation in the Prisoner’s Dilemma
BT  - an experimental comparison between pure and mixed strategies
T2  - Postprints der Universität Potsdam Wirtschafts- und Sozialwissenschaftliche Reihe
N2  - Cooperation is — despite not being predicted by game theory — a widely documented aspect of human behaviour in Prisoner’s Dilemma (PD) situations. This article presents a comparison between subjects restricted to playing pure strategies and subjects allowed to play mixed strategies in a one-shot symmetric PD laboratory experiment. Subjects interact with 10 other subjects and take their decisions all at once. Because subjects in the mixed-strategy treatment group are allowed to condition their level of cooperation more precisely on their beliefs about their counterparts’ level of cooperation, we predicted the cooperation rate in the mixed-strategy treatment group to be higher than in the pure-strategy control group. The results of our experiment reject our prediction: even after controlling for beliefs about the other subjects’ level of cooperation, we find that cooperation in the mixed-strategy group is lower than in the pure-strategy group. We also find, however, that subjects in the mixedstrategy group condition their cooperative behaviour more closely on their beliefs than in the pure-strategy group. In the mixed-strategy group, most subjects choose intermediate levels of cooperation.
T3  - Zweitveröffentlichungen der Universität Potsdam : Wirtschafts- und Sozialwissenschaftliche Reihe - 107 
KW  - cooperation
KW  - experiment
KW  - human behaviour
KW  - Prisoner's Dilemma
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-435929
SN  - 1867-5808
IS  - 107
ER  - 
TY  - JOUR
A1  - Heuer, Leonie
A1  - Orland, Andreas
T1  - Cooperation in the Prisoner’s Dilemma
BT  - an experimental comparison between pure and mixed strategies
JF  - Royal Society Open Science
N2  - Cooperation is — despite not being predicted by game theory — a widely documented aspect of human behaviour in Prisoner’s Dilemma (PD) situations. This article presents a comparison between subjects restricted to playing pure strategies and subjects allowed to play mixed strategies in a one-shot symmetric PD laboratory experiment. Subjects interact with 10 other subjects and take their decisions all at once. Because subjects in the mixed-strategy treatment group are allowed to condition their level of cooperation more precisely on their beliefs about their counterparts’ level of cooperation, we predicted the cooperation rate in the mixed-strategy treatment group to be higher than in the pure-strategy control group. The results of our experiment reject our prediction: even after controlling for beliefs about the other subjects’ level of cooperation, we find that cooperation in the mixed-strategy group is lower than in the pure-strategy group. We also find, however, that subjects in the mixedstrategy group condition their cooperative behaviour more closely on their beliefs than in the pure-strategy group. In the mixed-strategy group, most subjects choose intermediate levels of cooperation.
KW  - cooperation
KW  - experiment
KW  - human behaviour
KW  - Prisoner's Dilemma
Y1  - 2019
U6  - https://doi.org/10.1098/rsos.182142
SN  - 2054-5703
VL  - 6
PB  - Royal Soc. Publ.
CY  - London
ER  - 
TY  - RPRT
A1  - Bruttel, Lisa Verena
A1  - Felgendreher, Simon
A1  - Güth, Werner
A1  - Hertwig, Ralph
T1  - Strategic ignorance in repeated prisoners’ dilemma experiments and its effects on the dynamics of voluntary cooperation
T2  - CEPA Discussion Papers
N2  - Being ignorant of key aspects of a strategic interaction can represent an advantage rather than a handicap. We study one particular context in which ignorance can be beneficial: iterated strategic interactions in which voluntary cooperation may be sustained into the final round if players voluntarily forego knowledge about the time horizon. We experimentally examine this option to remain ignorant about the time horizon in a finitely repeated two-person prisoners’ dilemma game. We confirm that pairs without horizon knowledge avoid the drop in cooperation that otherwise occurs toward the end of the game. However, this effect is superposed by cooperation declining more rapidly in pairs without horizon knowledge during the middle phase of the game, especially if players do not know that the other player also wanted to remain ignorant of the time horizon.
T3  - CEPA Discussion Papers - 10 
KW  - strategic ignorance
KW  - cooperation
KW  - prisoners' dilemma
KW  - experiment
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-431881
SN  - 2628-653X
IS  - 10
ER  -